Three new suspects charged over Boston Marathon bombings

AUTHORITIES in Boston have made new arrests over the marathon bombings, detaining three suspects, including two college friends of Dzhokhar Tsarnaev, 19, who is accused of planting the bombs with his elder brother.

Two men, Azamat Tazhayakov and Dias Kadyrbayev, have been charged with conspiracy to obstruct justice by throwing away a backpack containing fireworks and a laptop computer belonging to Dzhokhar, one of two brothers suspected of carrying out the attack on 15 April.

Dzhokhar was captured on 19 April following a massive manhunt that brought the Boston area to a standstill.

His brother, Tamerlan, 26, was killed during an earlier police shootout.

Three people were killed and over 200 injured when two pressure-cooker bombs allegedly planted by the Tsarnaev brothers exploded near the marathon finish line in central Boston.

Dzhokhar has since been charged with using a weapon of mass destruction for his role in the attack and could face the death penalty.

Of the three new suspects arrested, two were said to be classmates of Dzhokhar who came to the US from Kazakhstan.

They were already in the custody of immigration authorities on allegations that they had breached the terms of their visas.

US prosecutors also charged a third man, Robel Phillipos, with making false statements to investigators, according to documents filed in federal court.

Police were said to be focusing on whether Dzhokhar's classmates helped him after the bombings by throwing away a backpack at his request. The backpack ended up in a local landfill.

The developments come after the police were reported to be searching a landfill in New Bedford, Massachusetts, last week.

The search came after Dzhokhar, who was found with serious injuries when he was captured, was questioned by investigators as he recovered in his hospital bed.